1. Field of the Invention
The present invention relates to a battery module for storage of electrochemical cells, including a cover assembly including an inner frame that encloses an end of the cells and applies a compressive force thereto.
2. Description of the Related Art
Battery packs provide power for various technologies ranging from portable electronics to renewable power systems and environmentally friendly vehicles. For example, hybrid electric vehicles (HEV) use a battery pack and an electric motor in conjunction with a combustion engine to increase fuel efficiency. Battery packs are formed of a plurality of battery modules, where each battery module includes several electrochemical cells. The cells are closely arranged in two or three dimensional arrays, and are electrically connected in series or in parallel. Likewise, the battery modules within a battery pack are electrically connected in series or in parallel.
Some conventional battery modules and battery packs have housings that are formed of welded steel components. However, the welding process used to form the housings can be expensive, and may also result in creation of undesirable conductive particles within the housing, and can sometimes have a high failure rate. It is desirable to provide an improved housing that is less expensive to manufacture and is reliable.